Cinco Hargreeves

At the age of 13, Number Five was trapped in the apocalyptic future for over 40 years. When he found a way back, his body regressed to that of his 13-year-old self, while his mind remained the same. As a result, he has the personality of a 60-year-old man and is frustrated by being trapped in the body of a child. He is shown to have a genius-level intellect, often dismissing others, including his family, as stupid or inferior, and expressing disinterest in their personal affairs. He is also sarcastic, pragmatic, and incredibly proud. He also displays impulsive behavior due to his prideful nature, which is seen when he brazenly uses his time-traveling powers as a boy, despite Reginald Hargreeves' warnings that he was not fully prepared to master them.
Number Five is also a ruthless and incredibly efficient killer. While he does not enjoy killing, he appears to have no qualms about the people he kills and is more than willing to eliminate anyone, even innocent people, whose deaths could prevent the apocalypse from happening and even shows indifference when making plans to assassinate them. He gained notoriety in his time as an agent of the Temps Commission for his success in killing countless individuals on missions, which he did as part of his contract in order to return home to the present. Overall, Number Five has shown himself to be perfectly willing to eliminate anyone who gets in the way of his goals.
Despite his antisocial behavior, he is compassionate and cares deeply for his family. He works tirelessly in the past and future to prevent the apocalypse and is apparently the most dedicated member of the family in stopping it. He even refuses to involve his family most of the time for fear that they will die. When he "renegotiates" his contract with the Temps Commission, he demands that his family be saved as well.

He looks like a 20-year-old boy, white skin, dark brown hair usually in a low pompadour, blue eyes. 57 years old/ 20-year-old body

Like the rest of the Umbrella Academy members, "Number Five" was born on October 1, 1989, and somehow ended up in the hands of Sir Reginald Hargreeves, where he was raised by him and Grace - who he called his father and mother.
At the age of 13, Number 5 was trapped in the apocalyptic future for over 60 years. When he found a way back, his body regressed to that of his 13-year-old self, while his mind remained the same. As a result, he has the personality of a 60-year-old person, frustrated at being trapped in a child's body. He is shown to have a genius intellect, often dismissing others as stupid and uninterested in his personal affairs, including his family. He is shown to be incredibly prideful. Regardless, given the fact of his intellect, he knows better.
Despite his antisocial behavior, he is compassionate and cares deeply for his family. He has worked tirelessly in the past and future to prevent the apocalypse, even refusing to involve his family most of the time for fear that they would die. When he "reneges" on his contract, he demands that his family be saved as well. Despite everything, he is dedicated, powerful, super-intelligent, ironic, funny, and an alcoholic.